Calender roll filling



April 19, 1932. J F|$H 1,854,509

CALENDER ROLL FILLIM Filed May 11, 1929 l ?atented Apr. 19, lfi

JAMES FISH, 0F LEOMINSTW, MASSACHUSETTS, AS SIGNOR T0 HENRY PHILIP SHOE- NECK, 0E DOBCHESTEB, MASSACHUSETTS carnnnnn Born slums Application filed. May 11, 1929. Serial No. 362,435.

This invention relates to. calenders and supercalenders and calender'rolls, but more specifically to an improved heat-resistant filling for such calender or supercalender rolls.

The usual calender or supercalender roll adopted for such purposes as calendering or I supercalendering paper or cloth and similar materials, and have proven' to be successful save in one particular. It has been observed that after the roll has been run for some time, the filling of paper, cotton, etc., begins to crack or check off in small pieces, especially near the ends of the roll, and this necessitates either regrinding the roll or refilling it. It has long ago been understood that this checkmg or cracking of the filling is due to the heating up of'the roll filling. At first this heating up of the roll filling was attributed to frictional heat generated on the surface of the filling by the passage of the paper under pressure throughthe nip of the rolls inthe calender, supercalender, or press rolls. How

ever, it was later shown and proven that if the filling of the roll be removed carefully, the crack ng or checking ofthe-roll filling is o more pronounced ator near the center radius than at the surface thereof. This indicated that the'cracking or checking of the filling was due to heat passing from the metal or steel core out through the filling of the roll.

To overcome'this, the steel core was drilled clear through from end to end, and watercooled. This resulted in greatly decreasing" the cracking or checking of the filling, but

did not entirely eliminate it. However, the

. life "of the core was greatly "increased, and

this water-cooling of filled press, calender, and supercalender rolls has come into general use.

To the end ofstill further decreasing the checking and cracking of the filling, and to still further increase the life of the filling, I have carried out numerous experiments over a long period of time, and have finally devised a special filling which is less suscepti; ble to cracking and checking than any heretotore used.

My invention may best be understood by reference to the accompanying drawings. Figure I is a front ,view of the usual calender 'or supercalender roll. In this figure, a is the core of'metal, (b) is the water-cooled channel, (a) is the two end plates for compressing the fillin (d). is some of the usual filling. FigureI is a side view o'f this same r0 The roll may be filled several methods.

The usual method is to cut out round secticns'from paper or cotton, such as shown in Figure III, mount them on the metal or steel core, and compressthem between the end plates. This is known as a lamination-filled roll. Another method is to wind paper or cotton cloth, etc., onto'and around the core. This method, however, has the disadvantage of leaving .an unsealed or lappedend or v seam. Still another method is to shrink onto the core a wool or woolen jacket, thus eliminating the seam or end flap. Finally rolls have been filled by using more or less plastic materials, like rubber, etc., to fill in the space between the end plates. v

However all of these filled rolls,'regardless of the filling used or of the method of filling, and even when water-cooled through the cor e, are not entirely satisfactory in that they still crack or check especially at or near the .ends

of the roll. and thus after altime render the filling defective and incapable of-further use until reground or refilled. It is to overcome this defect that I have devised my-present invention. v

According to it, I take a heat-resistant material, such as asbestos. either in the form of asbestos paper, asbestos cloth, pressed asbestos, or asbestos and a binder, or any asbestoscontaining material, or rubber, in the form of sheets, rubberimpregnated materials, or

pla'sticized rubber, or heat-resistant synthetic- 'res1ns either as such or comminuted with fillers or 'materials impregnated with such resins as bakelite for example, or any heatresistant material, and assemble it as part of the filling.

One form of practicing the invention is to I take some asbestos paper or asbestos cloth and cut'it into sections of the same size as the regular paper or cloth filling, and insert several of these laminations at or near the end of the paper or cloth filling, thus giving us a section of heat-resistant material at or near the endsof the regular filling. Such a heatresistant section is shown at (e) of Fig. I. The laminations used may be of any suitable thickness, and it has been found that asbestos paper of ten mils (0.010 inches). thickness is suitable. The width of the assembled lami-- nations may vary, and be as little as an inch or as great as 6 or 8 inches depending on the heat characteristics'of the press rolls,

A calender stack or supercale nder stack, with which it is used.

As to the 'exact location of the heatresistant sections, I have found that the best results are obtained by having them located atth'e'very end of the roll-filling, and a width of one inch gives very good results. However, I have found that good results may also be obtained by locating the heat-resistant sections a little nearer the center of the rolland somewhat in from the ends of the'roll. The effect of this heat-resistant section such as one made from asbestos, or asbestoscontaining material,bakelite or bakelite-containing material, or rubber or rubberized material, or any other heat-resistant material,

, resistant-material itself, being heat-resistant is to prevent the heat from passing from the metal end pieces to the regular filling of paper or cotton, thus preventing the cracking or checking of the'filling- This heat may come from either the high pressure steam used toheat the steel rolls usually found, in super-.v calenders, or it may come from steam sprays' or also from frictional heat. And the heatdoes not 'check'or crack, so that the life of the roll-filling is prolonged. In point of fact,

after many trials with this heat-insulated,

section, I have found that thelife of a rollfilling may be increased byfifty percent by its use.

It will beapparent, of course, that the heatresistant filllng desired thickness is obtained, or as a built-in section of .plasticized,materialior by other well known'means. Andlikewise, the in-, ventlon is applicable to rollshaving fillings.

made from laminated sections, wound rolls,

for shrunken j fillings, or plasticized fillings, oi fillings made in situ, or any type of filling,

however prepared or assembled. The invent1on may thus be practiced, ,on any filled roll of any type, irrespective-'M the nature of the 7 mg. v .The filling proper is usually made up of paper or cotton laminations, and -is herein after referred to as the mid-section ,in

v or section may be affixed to the roll either as laminated sheets, or-as material wound around the core until the.

order to distinguish it from the heat-resistant section, -which is usually located at or near ends of the filling.

By the term calender'roll I mean any roll used for pressing or calendering or supercalendering fibrous or other materials, .the roll having a filling of fibrous or other material. These rolls are quite generally used in supercalenders for finishing paper,

and are most generallyrun in contact with a metal or steel roll. However, some calender or supercalender stacks have two filled rolls running'in contact with eachother in order to make possible a finishing of both sides of the paper or fibrous sheet.

This invention is thus adapted to be used There .are varlous heat-resistant materials with ' as t that may be used in practicing my invention,

and these heat resistant-materials may be used in sections having varying widths, and located in various places along the core of the roll. or in the/filling thereof; and there are various other modifications in materials,

proportions. locations, widths, and so forth,

which may be used in practicing my invention, but all such variants are to be considered as within the spirit, scope, and purview of my invention, as defined in the appended claims. a

What I therefore claim and desireto secure by Letters Patenti's: v p

1. A calender roll filling composed of a wide, fibrous, substantially cellulosic midsection, and comparatively narrow sections .of heat-resistant material located at or near the ends thereof. v

2. A calender roll filling composed ofa wide, fibrous, substantially .cellulosic midsection, and comparatively narrow sections of asbestos material located at or near. the ends thereof. -In testimony whereofLI aflix my signature.

JAMES FISH. 

